subrepo: test & fix svn subrepo removal

mercurial/subrepo.py

@@ -1,582 +1,582 b''
 # subrepo.py - sub-repository handling for Mercurial
 #
 # Copyright 2009-2010 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 import errno, os, re, xml.dom.minidom, shutil, urlparse, posixpath
 from i18n import _
 import config, util, node, error, cmdutil
 hg = None
 
 nullstate = ('', '', 'empty')
 
 def state(ctx, ui):
     """return a state dict, mapping subrepo paths configured in .hgsub
     to tuple: (source from .hgsub, revision from .hgsubstate, kind
     (key in types dict))
     """
     p = config.config()
     def read(f, sections=None, remap=None):
         if f in ctx:
             p.parse(f, ctx[f].data(), sections, remap, read)
         else:
             raise util.Abort(_("subrepo spec file %s not found") % f)
 
     if '.hgsub' in ctx:
         read('.hgsub')
 
     for path, src in ui.configitems('subpaths'):
         p.set('subpaths', path, src, ui.configsource('subpaths', path))
 
     rev = {}
     if '.hgsubstate' in ctx:
         try:
             for l in ctx['.hgsubstate'].data().splitlines():
                 revision, path = l.split(" ", 1)
                 rev[path] = revision
         except IOError, err:
             if err.errno != errno.ENOENT:
                 raise
 
     state = {}
     for path, src in p[''].items():
         kind = 'hg'
         if src.startswith('['):
             if ']' not in src:
                 raise util.Abort(_('missing ] in subrepo source'))
             kind, src = src.split(']', 1)
             kind = kind[1:]
 
         for pattern, repl in p.items('subpaths'):
             # Turn r'C:\foo\bar' into r'C:\\foo\\bar' since re.sub
             # does a string decode.
             repl = repl.encode('string-escape')
             # However, we still want to allow back references to go
             # through unharmed, so we turn r'\\1' into r'\1'. Again,
             # extra escapes are needed because re.sub string decodes.
             repl = re.sub(r'\\\\([0-9]+)', r'\\\1', repl)
             try:
                 src = re.sub(pattern, repl, src, 1)
             except re.error, e:
                 raise util.Abort(_("bad subrepository pattern in %s: %s")
                                  % (p.source('subpaths', pattern), e))
 
         state[path] = (src.strip(), rev.get(path, ''), kind)
 
     return state
 
 def writestate(repo, state):
     """rewrite .hgsubstate in (outer) repo with these subrepo states"""
     repo.wwrite('.hgsubstate',
                 ''.join(['%s %s\n' % (state[s][1], s)
                          for s in sorted(state)]), '')
 
 def submerge(repo, wctx, mctx, actx):
     """delegated from merge.applyupdates: merging of .hgsubstate file
     in working context, merging context and ancestor context"""
     if mctx == actx: # backwards?
         actx = wctx.p1()
     s1 = wctx.substate
     s2 = mctx.substate
     sa = actx.substate
     sm = {}
 
     repo.ui.debug("subrepo merge %s %s %s\n" % (wctx, mctx, actx))
 
     def debug(s, msg, r=""):
         if r:
             r = "%s:%s:%s" % r
         repo.ui.debug("  subrepo %s: %s %s\n" % (s, msg, r))
 
     for s, l in s1.items():
         a = sa.get(s, nullstate)
         ld = l # local state with possible dirty flag for compares
         if wctx.sub(s).dirty():
             ld = (l[0], l[1] + "+")
         if wctx == actx: # overwrite
             a = ld
 
         if s in s2:
             r = s2[s]
             if ld == r or r == a: # no change or local is newer
                 sm[s] = l
                 continue
             elif ld == a: # other side changed
                 debug(s, "other changed, get", r)
                 wctx.sub(s).get(r)
                 sm[s] = r
             elif ld[0] != r[0]: # sources differ
                 if repo.ui.promptchoice(
                     _(' subrepository sources for %s differ\n'
                       'use (l)ocal source (%s) or (r)emote source (%s)?')
                       % (s, l[0], r[0]),
                       (_('&Local'), _('&Remote')), 0):
                     debug(s, "prompt changed, get", r)
                     wctx.sub(s).get(r)
                     sm[s] = r
             elif ld[1] == a[1]: # local side is unchanged
                 debug(s, "other side changed, get", r)
                 wctx.sub(s).get(r)
                 sm[s] = r
             else:
                 debug(s, "both sides changed, merge with", r)
                 wctx.sub(s).merge(r)
                 sm[s] = l
         elif ld == a: # remote removed, local unchanged
             debug(s, "remote removed, remove")
             wctx.sub(s).remove()
         else:
             if repo.ui.promptchoice(
                 _(' local changed subrepository %s which remote removed\n'
                   'use (c)hanged version or (d)elete?') % s,
                 (_('&Changed'), _('&Delete')), 0):
                 debug(s, "prompt remove")
                 wctx.sub(s).remove()
 
     for s, r in s2.items():
         if s in s1:
             continue
         elif s not in sa:
             debug(s, "remote added, get", r)
             mctx.sub(s).get(r)
             sm[s] = r
         elif r != sa[s]:
             if repo.ui.promptchoice(
                 _(' remote changed subrepository %s which local removed\n'
                   'use (c)hanged version or (d)elete?') % s,
                 (_('&Changed'), _('&Delete')), 0) == 0:
                 debug(s, "prompt recreate", r)
                 wctx.sub(s).get(r)
                 sm[s] = r
 
     # record merged .hgsubstate
     writestate(repo, sm)
 
 def reporelpath(repo):
     """return path to this (sub)repo as seen from outermost repo"""
     parent = repo
     while hasattr(parent, '_subparent'):
         parent = parent._subparent
     return repo.root[len(parent.root)+1:]
 
 def subrelpath(sub):
     """return path to this subrepo as seen from outermost repo"""
     if not hasattr(sub, '_repo'):
         return sub._path
     return reporelpath(sub._repo)
 
 def _abssource(repo, push=False, abort=True):
     """return pull/push path of repo - either based on parent repo .hgsub info
     or on the top repo config. Abort or return None if no source found."""
     if hasattr(repo, '_subparent'):
         source = repo._subsource
         if source.startswith('/') or '://' in source:
             return source
         parent = _abssource(repo._subparent, push, abort=False)
         if parent:
             if '://' in parent:
                 if parent[-1] == '/':
                     parent = parent[:-1]
                 r = urlparse.urlparse(parent + '/' + source)
                 r = urlparse.urlunparse((r[0], r[1],
                                          posixpath.normpath(r[2]),
                                          r[3], r[4], r[5]))
                 return r
             else: # plain file system path
                 return posixpath.normpath(os.path.join(parent, repo._subsource))
     else: # recursion reached top repo
         if hasattr(repo, '_subtoppath'):
             return repo._subtoppath
         if push and repo.ui.config('paths', 'default-push'):
             return repo.ui.config('paths', 'default-push')
         if repo.ui.config('paths', 'default'):
             return repo.ui.config('paths', 'default')
     if abort:
         raise util.Abort(_("default path for subrepository %s not found") %
             reporelpath(repo))
 
 def itersubrepos(ctx1, ctx2):
     """find subrepos in ctx1 or ctx2"""
     # Create a (subpath, ctx) mapping where we prefer subpaths from
     # ctx1. The subpaths from ctx2 are important when the .hgsub file
     # has been modified (in ctx2) but not yet committed (in ctx1).
     subpaths = dict.fromkeys(ctx2.substate, ctx2)
     subpaths.update(dict.fromkeys(ctx1.substate, ctx1))
     for subpath, ctx in sorted(subpaths.iteritems()):
         yield subpath, ctx.sub(subpath)
 
 def subrepo(ctx, path):
     """return instance of the right subrepo class for subrepo in path"""
     # subrepo inherently violates our import layering rules
     # because it wants to make repo objects from deep inside the stack
     # so we manually delay the circular imports to not break
     # scripts that don't use our demand-loading
     global hg
     import hg as h
     hg = h
 
     util.path_auditor(ctx._repo.root)(path)
     state = ctx.substate.get(path, nullstate)
     if state[2] not in types:
         raise util.Abort(_('unknown subrepo type %s') % state[2])
     return types[state[2]](ctx, path, state[:2])
 
 # subrepo classes need to implement the following abstract class:
 
 class abstractsubrepo(object):
 
     def dirty(self):
         """returns true if the dirstate of the subrepo does not match
         current stored state
         """
         raise NotImplementedError
 
     def checknested(self, path):
         """check if path is a subrepository within this repository"""
         return False
 
     def commit(self, text, user, date):
         """commit the current changes to the subrepo with the given
         log message. Use given user and date if possible. Return the
         new state of the subrepo.
         """
         raise NotImplementedError
 
     def remove(self):
         """remove the subrepo
 
         (should verify the dirstate is not dirty first)
         """
         raise NotImplementedError
 
     def get(self, state):
         """run whatever commands are needed to put the subrepo into
         this state
         """
         raise NotImplementedError
 
     def merge(self, state):
         """merge currently-saved state with the new state."""
         raise NotImplementedError
 
     def push(self, force):
         """perform whatever action is analogous to 'hg push'
 
         This may be a no-op on some systems.
         """
         raise NotImplementedError
 
     def add(self, ui, match, dryrun, prefix):
         return []
 
     def status(self, rev2, **opts):
         return [], [], [], [], [], [], []
 
     def diff(self, diffopts, node2, match, prefix, **opts):
         pass
 
     def outgoing(self, ui, dest, opts):
         return 1
 
     def incoming(self, ui, source, opts):
         return 1
 
     def files(self):
         """return filename iterator"""
         raise NotImplementedError
 
     def filedata(self, name):
         """return file data"""
         raise NotImplementedError
 
     def fileflags(self, name):
         """return file flags"""
         return ''
 
     def archive(self, archiver, prefix):
         for name in self.files():
             flags = self.fileflags(name)
             mode = 'x' in flags and 0755 or 0644
             symlink = 'l' in flags
             archiver.addfile(os.path.join(prefix, self._path, name),
                              mode, symlink, self.filedata(name))
 
 
 class hgsubrepo(abstractsubrepo):
     def __init__(self, ctx, path, state):
         self._path = path
         self._state = state
         r = ctx._repo
         root = r.wjoin(path)
         create = False
         if not os.path.exists(os.path.join(root, '.hg')):
             create = True
             util.makedirs(root)
         self._repo = hg.repository(r.ui, root, create=create)
         self._repo._subparent = r
         self._repo._subsource = state[0]
 
         if create:
             fp = self._repo.opener("hgrc", "w", text=True)
             fp.write('[paths]\n')
 
             def addpathconfig(key, value):
                 if value:
                     fp.write('%s = %s\n' % (key, value))
                     self._repo.ui.setconfig('paths', key, value)
 
             defpath = _abssource(self._repo, abort=False)
             defpushpath = _abssource(self._repo, True, abort=False)
             addpathconfig('default', defpath)
             if defpath != defpushpath:
                 addpathconfig('default-push', defpushpath)
             fp.close()
 
     def add(self, ui, match, dryrun, prefix):
         return cmdutil.add(ui, self._repo, match, dryrun, True,
                            os.path.join(prefix, self._path))
 
     def status(self, rev2, **opts):
         try:
             rev1 = self._state[1]
             ctx1 = self._repo[rev1]
             ctx2 = self._repo[rev2]
             return self._repo.status(ctx1, ctx2, **opts)
         except error.RepoLookupError, inst:
             self._repo.ui.warn(_('warning: error "%s" in subrepository "%s"\n')
                                % (inst, subrelpath(self)))
             return [], [], [], [], [], [], []
 
     def diff(self, diffopts, node2, match, prefix, **opts):
         try:
             node1 = node.bin(self._state[1])
             # We currently expect node2 to come from substate and be
             # in hex format
             if node2 is not None:
                 node2 = node.bin(node2)
             cmdutil.diffordiffstat(self._repo.ui, self._repo, diffopts,
                                    node1, node2, match,
                                    prefix=os.path.join(prefix, self._path),
                                    listsubrepos=True, **opts)
         except error.RepoLookupError, inst:
             self._repo.ui.warn(_('warning: error "%s" in subrepository "%s"\n')
                                % (inst, subrelpath(self)))
 
     def archive(self, archiver, prefix):
         abstractsubrepo.archive(self, archiver, prefix)
 
         rev = self._state[1]
         ctx = self._repo[rev]
         for subpath in ctx.substate:
             s = subrepo(ctx, subpath)
             s.archive(archiver, os.path.join(prefix, self._path))
 
     def dirty(self):
         r = self._state[1]
         if r == '':
             return True
         w = self._repo[None]
         if w.p1() != self._repo[r]: # version checked out change
             return True
         return w.dirty() # working directory changed
 
     def checknested(self, path):
         return self._repo._checknested(self._repo.wjoin(path))
 
     def commit(self, text, user, date):
         self._repo.ui.debug("committing subrepo %s\n" % subrelpath(self))
         n = self._repo.commit(text, user, date)
         if not n:
             return self._repo['.'].hex() # different version checked out
         return node.hex(n)
 
     def remove(self):
         # we can't fully delete the repository as it may contain
         # local-only history
         self._repo.ui.note(_('removing subrepo %s\n') % subrelpath(self))
         hg.clean(self._repo, node.nullid, False)
 
     def _get(self, state):
         source, revision, kind = state
         try:
             self._repo.lookup(revision)
         except error.RepoError:
             self._repo._subsource = source
             srcurl = _abssource(self._repo)
             self._repo.ui.status(_('pulling subrepo %s from %s\n')
                                  % (subrelpath(self), srcurl))
             other = hg.repository(self._repo.ui, srcurl)
             self._repo.pull(other)
 
     def get(self, state):
         self._get(state)
         source, revision, kind = state
         self._repo.ui.debug("getting subrepo %s\n" % self._path)
         hg.clean(self._repo, revision, False)
 
     def merge(self, state):
         self._get(state)
         cur = self._repo['.']
         dst = self._repo[state[1]]
         anc = dst.ancestor(cur)
         if anc == cur:
             self._repo.ui.debug("updating subrepo %s\n" % subrelpath(self))
             hg.update(self._repo, state[1])
         elif anc == dst:
             self._repo.ui.debug("skipping subrepo %s\n" % subrelpath(self))
         else:
             self._repo.ui.debug("merging subrepo %s\n" % subrelpath(self))
             hg.merge(self._repo, state[1], remind=False)
 
     def push(self, force):
         # push subrepos depth-first for coherent ordering
         c = self._repo['']
         subs = c.substate # only repos that are committed
         for s in sorted(subs):
             if not c.sub(s).push(force):
                 return False
 
         dsturl = _abssource(self._repo, True)
         self._repo.ui.status(_('pushing subrepo %s to %s\n') %
             (subrelpath(self), dsturl))
         other = hg.repository(self._repo.ui, dsturl)
         return self._repo.push(other, force)
 
     def outgoing(self, ui, dest, opts):
         return hg.outgoing(ui, self._repo, _abssource(self._repo, True), opts)
 
     def incoming(self, ui, source, opts):
         return hg.incoming(ui, self._repo, _abssource(self._repo, False), opts)
 
     def files(self):
         rev = self._state[1]
         ctx = self._repo[rev]
         return ctx.manifest()
 
     def filedata(self, name):
         rev = self._state[1]
         return self._repo[rev][name].data()
 
     def fileflags(self, name):
         rev = self._state[1]
         ctx = self._repo[rev]
         return ctx.flags(name)
 
 
 class svnsubrepo(abstractsubrepo):
     def __init__(self, ctx, path, state):
         self._path = path
         self._state = state
         self._ctx = ctx
         self._ui = ctx._repo.ui
 
     def _svncommand(self, commands, filename=''):
         path = os.path.join(self._ctx._repo.origroot, self._path, filename)
         cmd = ['svn'] + commands + [path]
         cmd = [util.shellquote(arg) for arg in cmd]
         cmd = util.quotecommand(' '.join(cmd))
         env = dict(os.environ)
         # Avoid localized output, preserve current locale for everything else.
         env['LC_MESSAGES'] = 'C'
         write, read, err = util.popen3(cmd, env=env, newlines=True)
         retdata = read.read()
         err = err.read().strip()
         if err:
             raise util.Abort(err)
         return retdata
 
     def _wcrev(self):
         output = self._svncommand(['info', '--xml'])
         doc = xml.dom.minidom.parseString(output)
         entries = doc.getElementsByTagName('entry')
         if not entries:
             return '0'
         return str(entries[0].getAttribute('revision')) or '0'
 
     def _wcchanged(self):
         """Return (changes, extchanges) where changes is True
         if the working directory was changed, and extchanges is
         True if any of these changes concern an external entry.
         """
         output = self._svncommand(['status', '--xml'])
         externals, changes = [], []
         doc = xml.dom.minidom.parseString(output)
         for e in doc.getElementsByTagName('entry'):
             s = e.getElementsByTagName('wc-status')
             if not s:
                 continue
             item = s[0].getAttribute('item')
             props = s[0].getAttribute('props')
             path = e.getAttribute('path')
             if item == 'external':
                 externals.append(path)
             if (item not in ('', 'normal', 'unversioned', 'external')
                 or props not in ('', 'none')):
                 changes.append(path)
         for path in changes:
             for ext in externals:
                 if path == ext or path.startswith(ext + os.sep):
                     return True, True
         return bool(changes), False
 
     def dirty(self):
         if self._wcrev() == self._state[1] and not self._wcchanged()[0]:
             return False
         return True
 
     def commit(self, text, user, date):
         # user and date are out of our hands since svn is centralized
         changed, extchanged = self._wcchanged()
         if not changed:
             return self._wcrev()
         if extchanged:
             # Do not try to commit externals
             raise util.Abort(_('cannot commit svn externals'))
         commitinfo = self._svncommand(['commit', '-m', text])
         self._ui.status(commitinfo)
         newrev = re.search('Committed revision ([0-9]+).', commitinfo)
         if not newrev:
             raise util.Abort(commitinfo.splitlines()[-1])
         newrev = newrev.groups()[0]
         self._ui.status(self._svncommand(['update', '-r', newrev]))
         return newrev
 
     def remove(self):
         if self.dirty():
             self._ui.warn(_('not removing repo %s because '
                             'it has changes.\n' % self._path))
             return
         self._ui.note(_('removing subrepo %s\n') % self._path)
-        shutil.rmtree(self._ctx.repo.join(self._path))
+        shutil.rmtree(self._ctx._repo.wjoin(self._path))
 
     def get(self, state):
         status = self._svncommand(['checkout', state[0], '--revision', state[1]])
         if not re.search('Checked out revision [0-9]+.', status):
             raise util.Abort(status.splitlines()[-1])
         self._ui.status(status)
 
     def merge(self, state):
         old = int(self._state[1])
         new = int(state[1])
         if new > old:
             self.get(state)
 
     def push(self, force):
         # push is a no-op for SVN
         return True
 
     def files(self):
         output = self._svncommand(['list'])
         # This works because svn forbids \n in filenames.
         return output.splitlines()
 
     def filedata(self, name):
         return self._svncommand(['cat'], name)
 
 
 types = {
     'hg': hgsubrepo,
     'svn': svnsubrepo,
     }

tests/test-subrepo-svn.t

@@ -1,219 +1,224 b''
   $ "$TESTDIR/hghave" svn || exit 80
 
   $ fix_path()
   > {
   >     tr '\\' /
   > }
 
 SVN wants all paths to start with a slash. Unfortunately, Windows ones
 don't. Handle that.
 
   $ escapedwd=`pwd | fix_path`
   $ expr "$escapedwd" : '\/' > /dev/null || escapedwd="/$escapedwd"
   $ escapedwd=`python -c "import urllib, sys; sys.stdout.write(urllib.quote(sys.argv[1]))" "$escapedwd"`
 
 create subversion repo
 
   $ SVNREPO="file://$escapedwd/svn-repo"
   $ WCROOT="`pwd`/svn-wc"
   $ svnadmin create svn-repo
   $ svn co "$SVNREPO" svn-wc
   Checked out revision 0.
   $ cd svn-wc
   $ mkdir src
   $ echo alpha > src/alpha
   $ svn add src
   A         src
   A         src/alpha
   $ mkdir externals
   $ echo other > externals/other
   $ svn add externals
   A         externals
   A         externals/other
   $ svn ci -m 'Add alpha'
   Adding         externals
   Adding         externals/other
   Adding         src
   Adding         src/alpha
   Transmitting file data ..
   Committed revision 1.
   $ svn up
   At revision 1.
   $ echo "externals -r1 $SVNREPO/externals" > extdef
   $ svn propset -F extdef svn:externals src
   property 'svn:externals' set on 'src'
   $ svn ci -m 'Setting externals'
   Sending        src
   
   Committed revision 2.
   $ cd ..
 
 create hg repo
 
   $ mkdir sub
   $ cd sub
   $ hg init t
   $ cd t
 
 first revision, no sub
 
   $ echo a > a
   $ hg ci -Am0
   adding a
 
 add first svn sub with leading whitespaces
 
   $ echo "s = [svn]       $SVNREPO/src" >> .hgsub
   $ svn co --quiet "$SVNREPO"/src s
   $ hg add .hgsub
   $ hg ci -m1
   committing subrepository s
 
 make sure we avoid empty commits (issue2445)
 
   $ hg sum
   parent: 1:* tip (glob)
    1
   branch: default
   commit: (clean)
   update: (current)
   $ hg ci -moops
   nothing changed
   [1]
 
 debugsub
 
   $ hg debugsub
   path s
    source   file://*/svn-repo/src (glob)
    revision 2
 
 change file in svn and hg, commit
 
   $ echo a >> a
   $ echo alpha >> s/alpha
   $ hg sum
   parent: 1:* tip (glob)
    1
   branch: default
   commit: 1 modified, 1 subrepos
   update: (current)
   $ hg commit -m 'Message!'
   committing subrepository s
   Sending*s/alpha (glob)
   Transmitting file data .
   Committed revision 3.
   
   Fetching external item into '$TESTTMP/sub/t/s/externals'
   External at revision 1.
   
   At revision 3.
   $ hg debugsub
   path s
    source   file://*/svn-repo/src (glob)
    revision 3
 
   $ echo a > s/a
 
 should be empty despite change to s/a
 
   $ hg st
 
 add a commit from svn
 
   $ cd "$WCROOT"/src
   $ svn up
   U    alpha
   
   Fetching external item into 'externals'
   A    externals/other
   Updated external to revision 1.
   
   Updated to revision 3.
   $ echo xyz >> alpha
   $ svn propset svn:mime-type 'text/xml' alpha
   property 'svn:mime-type' set on 'alpha'
   $ svn ci -m 'amend a from svn'
   Sending        src/alpha
   Transmitting file data .
   Committed revision 4.
   $ cd ../../sub/t
 
 this commit from hg will fail
 
   $ echo zzz >> s/alpha
   $ hg ci -m 'amend alpha from hg'
   committing subrepository s
   abort: svn: Commit failed (details follow):
   svn: (Out of date)?.*/src/alpha.*(is out of date)? (re)
   [255]
   $ svn revert -q s/alpha
 
 this commit fails because of meta changes
 
   $ svn propset svn:mime-type 'text/html' s/alpha
   property 'svn:mime-type' set on 's/alpha'
   $ hg ci -m 'amend alpha from hg'
   committing subrepository s
   abort: svn: Commit failed (details follow):
   svn: (Out of date)?.*/src/alpha.*(is out of date)? (re)
   [255]
   $ svn revert -q s/alpha
 
 this commit fails because of externals changes
 
   $ echo zzz > s/externals/other
   $ hg ci -m 'amend externals from hg'
   committing subrepository s
   abort: cannot commit svn externals
   [255]
   $ hg diff --subrepos -r 1:2 | grep -v diff
   --- a/.hgsubstate	Thu Jan 01 00:00:00 1970 +0000
   +++ b/.hgsubstate	Thu Jan 01 00:00:00 1970 +0000
   @@ -1,1 +1,1 @@
   -2 s
   +3 s
   --- a/a	Thu Jan 01 00:00:00 1970 +0000
   +++ b/a	Thu Jan 01 00:00:00 1970 +0000
   @@ -1,1 +1,2 @@
    a
   +a
   $ svn revert -q s/externals/other
 
 this commit fails because of externals meta changes
 
   $ svn propset svn:mime-type 'text/html' s/externals/other
   property 'svn:mime-type' set on 's/externals/other'
   $ hg ci -m 'amend externals from hg'
   committing subrepository s
   abort: cannot commit svn externals
   [255]
   $ svn revert -q s/externals/other
 
 clone
 
   $ cd ..
   $ hg clone t tc | fix_path
   updating to branch default
   A    tc/s/alpha
    U   tc/s
   
   Fetching external item into 'tc/s/externals'
   A    tc/s/externals/other
   Checked out external at revision 1.
   
   Checked out revision 3.
   3 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cd tc
 
 debugsub in clone
 
   $ hg debugsub
   path s
    source   file://*/svn-repo/src (glob)
    revision 3
 
 verify subrepo is contained within the repo directory
 
   $ python -c "import os.path; print os.path.exists('s')"
   True
+
+update to nullrev (must delete the subrepo)
+
+  $ hg up null
+  0 files updated, 0 files merged, 3 files removed, 0 files unresolved